Strip Cropping Reduces Soil Erosion, Increases Corn Yields

Reprinted from No-Till Farmer – By Dan Zinkland posted on June 1, 2010

Herbicide-tolerant crops make managing strips easier, but the system works best for no-tillers with smaller farms and planters

No-tillers who strip intercrop often do so to increase corn yields — the result of exposing more outside rows of corn to the sun.

But Minburn, Iowa, no-tiller and ridge-tiller Craig Fleishman strip intercrops primarily to reduce erosion from water moving down the gently rolling hills on two of his farms.

“The strips break up the wind and the rain and the erosion that create gullies,” Fleishman says. “The 12 rows of corn slow the flow of water moving down between the hills.”

Reducing Soil Erosion

Fleishman divides the two farms into three blocks. He strips two of the blocks and no-tills the entire third block to corn. He moves the block of corn each year

“Neither farm is classified as highly erodible,” Fleishman says. “But we tend to get some gully washouts.

“It’s not practical to put a grass waterway in every spot where that could happen. The corn stalks in the strips break up the drainage pattern of the land.”

He started strip intercropping in 2000 and he alternates 12 rows of corn with 12 rows of soybeans. Fleishman plants the strips of corn first without GPS.

“I know where everything is,” Fleishman says. “You just go out there and plant. I go down the old rows.”

Herbicide Tolerance Helps

Roundup Ready and LibertyLink corn and soybeans make strip intercropping easier, but Fleishman has strip intercropped with conventional soybeans.

“You just have to be on your toes with conventional soybeans,” he says. “Roundup Ready, GPS and auto-steer make it a lot easier to strip intercrop than for those guys who were doing it back in the 1980s.

“It’s not really widely practiced now. With larger planters, guys want to get over the rows faster. If you have 24-row-wide strips in corn, you are probably going to lose out on the edge-effect benefit.”

Ideally, four rows of corn alternating with four rows of soybeans would provide the maximum number of edges in a field, Fleishman says. But he says 12-row-wide strips work well on his farm.

Strips Take Time

If a no-tiller wants to strip intercrop, start with one field, Fleishman suggests.

“It’s a good system, but it’s not for everybody,” he says. “If you don’t have much patience, it’s probably not for you.

“In my area, the trend is toward larger planters. Unless you can plant two crops at the same time, it’s going to be hard to sell strip intercropping.”

Long-time no-tiller Jim House says the system worked well on his farm.

“Strip intercropping has dual benefits of high yields and preventing erosion,” says the Port Stanley, Ont., Canada, no-tiller, who began strip intercropping corn, soybeans and winter wheat 17 years ago.

Wheat lowered the yield of soybeans, House says, so he stripped corn and soybeans. He used three 21-inch rows for corn in strips 7.5 feet wide. He planted the outside rows to twin rows spaced 7.5 inches apart.

The soybeans were planted on 15-inch rows in strips 15 feet wide. Because the wider strips of soybeans flanked the corn, House ended up with soybeans on soybeans on half of his beans.

House planted 32,000 kernels of corn per acre in the center row and 50,000 per acre in the outside rows to maximize exposure to the sun.

Planting just three 21-inch corn rows exposed more corn to the sunlight than wider strips to get the “edge effect.”

Higher Corn Yields

“The corn in the strips consistently yielded 100 bushels per acre more than my neighbor’s corn planted in whole fields,” says House, adding corn yields ran as high as 400 bushels per acre. “From 1999 to 2008, the corn in strips averaged 275 to 300 bushels per acre.”

He attributes higher yields to more exposure to sun and higher plant populations.

“We never changed our fertilizer program much from that of our neighbors,” he says. “We ran a good 200 pounds of nitrogen per acre.”

When he started strip intercropping, it was tough to find compatible herbicides for corn, soybeans and wheat.

“Then Roundup Ready corn came on the market,” he says.

House harvested soybeans first and then combined corn with a head he built. Because outside rows of corn shaded the soybeans, soybean yields were a little lower than seen in a full field of soybeans, he says.

House believes in strip intercropping, but he says it’s not for everyone, particularly no-tillers with thousands of acres.